R. Ancimer et al., Decomposition of measured velocity fields within spark ignition engines using discrete wavelet transforms, EXP FLUID, 30(2), 2001, pp. 237-238
Two techniques are generally used to extract turbulence information from en
gine flows: the ensemble and cyclic, or scale-based average. A new method i
s proposed here that uses an energy-based cyclic averaging technique. The e
nergy-based filter proves to be superior in removing the coherent events as
sociated with the cycle-to-cycle variations in the mean flow.